if you have the spare cash, I'd get all of them though. I'll admit that Sierra Madre is an acquired taste. However, the characters from each DLC intertwine and you get to meet the dickhole that put the Vegas branch of the Brotherhood of Steel in such a bind.

re: Which DLC should I get for fallout new vegas?(Posted by sbr2 on 1/6/13 at 10:43 pm to CornDogCologne)

Shut up Corndog, no one is going to stand in the way of my Sierra Madre hate. The strengths of NV (open-world, multiple options, not nigh invincible enemies) are all taken away. Much like the Pitt DLC from FO3 you lose everything and are trapped in a small uninteresting area.